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ABSTRACT: We demonstrate experimentally that the energy from a highly localized free-electron-beam excitation can be converted via a planar plasmonic metamaterial to a low-divergence free-space light beam. This emission, which emanates from a collectively oscillating coupled metamolecule nanoantenna ensemble much larger in size than the initial excitation, is distinctly different from cathodoluminescence and bears some similarity with laser light. It offers a novel, flexible paradigm for the development of scalable, threshold-free light sources.
Physical Review Letters 11/2012; 109(21):217401. · 7.37 Impact Factor
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ABSTRACT: A pair of coupled gold nanorods excited by a beam of free electrons acts as a transmitting Hertzian antenna in the optical part of the spectrum. Significantly enhanced resonant emission is observed from the antenna when the electron beam is injected around the junction between the rods, where the local density of electromagnetic states is elevated.
Nano Letters 09/2010; 10(9):3250-2. · 13.20 Impact Factor
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ABSTRACT: We have prepared and studied the PbF(2):(Yb(3+),Er(3+)) co-doped nanoparticles, with chemical formula (Yb-Er)(x)Pb(1-x)F(2+x), where x = 0.29, Yb(3+)/Er(3+) = 6, and estimated the energy efficiency for their cathodoluminescence, mostly of Yb(3+), and up-conversion photoluminescence of Er(3+) to reach more than 0.5% and 20%, respectively, which may be the highest to date for rare-earth doped nanoparticles. Electron beam induced temperature rise in the nanoparticles has been estimated by measuring the ratio of green emission bands of Er(3+). These high efficiencies are due to high doping level of nanoparticles and due to low phonon energy of the PbF(2) host.
Optics Express 04/2010; 18(9):8836-46. · 3.59 Impact Factor
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ABSTRACT: Recently demonstrated 'light-wells'—free-electron-driven tuneable nanoscale light sources—generate optical photons as electrons travel down a nano-hole through a metal–dielectric multilayer structure. We report here on the application of boundary element modeling methods to the simulation of light-well output characteristics. The model is found to successfully reproduce the key features observed in experiment and as such will aid in the development and optimization of future device structures.
Journal of optics 01/2010; 12(2):024012. · 1.57 Impact Factor
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ABSTRACT: The passage of a free-electron beam through a nanohole in a periodically layered metal-dielectric structure creates a new type of tunable, nanoscale radiation source--a "light well". In the reported demonstration, tunable light is generated at an intensity of approximately 200 W/cm(2) as electrons with energies in the 20-40 keV range are injected into gold-silica well structures with a lateral size of just a few hundred nanometers.
Physical Review Letters 09/2009; 103(11):113901. · 7.37 Impact Factor
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ABSTRACT: The passage of a free-electron beam through a nano-hole in a periodically layered metal/dielectric structure creates a new type of tuneable, nanoscale radiation source - a 'light-well'. With a lateral size of just a few hundred nanometers, and an emission intensity of ~200 W/cm^2 such light-wells may be employed in nanophotonic circuits as chip-scale sources, or in densely packed ensembles for optical memory and display applications. Comment: 4 pages, 3 figures
07/2009;
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Z. L. Sámson,
J Zhang, G Adamo,
Takashi Uchino,
B. Gholipour,
K. Knight,
C Huang,
F. Angelis,
K. F. MacDonald,
Peter Ashburn,
E. Fabrizio,
D W Hewak,
N I Zheludev
